Polymer Concrete with Fiber Reinforcement for Bridge Deck Closure Joints in Accelerated Bridge Construction

An experimental program was conducted to investigate the bond strength of epoxy-coated deformed bar reinforcement embedded in a commercially available polymer concrete with fiber reinforcement (PCFR) to assess its suitability as a closure pour material for accelerated bridge construction (ABC) applications. For projects that must be completed in short overnight closure windows, the rapid strength development of polymer concretes, which can typically be designed to achieve a majority of their design strength in several hours, may be advantageous compared to cementitious closure pour materials such as ultrahigh-performance concrete (UHPC). Test specimens were sized so they could be conditioned to different test temperatures using conventional laboratory equipment and tested on a universal testing machine under precise displacement control. The test series was designed as a rotatable central composite design to examine the effects of noncontact splice length, side cover, bar size, and test temperature on noncontact splice strength. Based on a statistical analysis of the collected data, epoxy-coated deformed bar reinforcement embedded in the commercially available PCFR, overlapped for at least six bar diameters, and with at least three bar diameters of clear cover was able to develop the nominal yield stress of the reinforcement for temperatures up to the extent of the experimental design space, 44°C (110°F). Beyond this temperature, additional splice length or bar cover may be required to achieve the nominal yield strength of the bar; however, further testing, especially at elevated temperatures, is necessary. These results support the use of similar closure joint geometries for both UHPC and PCFR. The capability of PCFR to achieve the same joint geometry as UHPC increases the potential options for a given ABC project, especially when very rapid strength gain is required.